The present invention relates to a method and device for automatically composing a piece of music in accordance with various musical conditions.
With a widespread use of personal computers, everyone has now come to be able to freely enjoy various types of music through the “computer music” technique, which uses a computer to play a musical instrument, compose a piece of music (music piece), arrange a composed music piece and synthesize to a tone color. Particularly, in the field of music composition using a computer, even people without expert knowledge of music can compose easily by just entering and setting various musical conditions as directed by the computer. In addition, automatic music composing devices have recently been proposed which analyze characteristics of a melody to an original music piece by classifying the melody into harmonic and non-harmonic tones and further classifying the non-harmonic tones. The proposed automatic music composing devices then synthesize a new melody in accordance with the analysis results and chord progression to thereby automatically compose a music piece.
For example, Japanese Patent Laid-open Publications Nos. SHO-63-311395, SHO-63-250696 and HEI-1-167783 disclose automatic composing techniques which take non-harmonic tones into account as mentioned above. Further, in U.S. Pat. No. 4,926,737, there is disclosed a technique which extracts characteristic parameters out of a motif melody and creates a new melody on the basis of the thus-extracted parameters. In addition, Japanese Patent Laid-Open Publication No. HEI-3119381 teaches an automatic composing technique which analyzes time series forming a melody of an original music piece so as to calculate linear predictive coefficients and create a new melody on the basis of the calculated linear predictive coefficients. Furthermore, Japanese Patent Laid-open Publication Nos. HEI-4-9892 and HEI-4-9893 disclose technique of analyzing a melody on the basis of chords and tonality in a melody. All of the prior techniques create a new melody in accordance with a given chord progression and by use of extracted characteristic parameters or analyzed data of a melody. These techniques, however, required user's special knowledge of music.
Furthermore, Japanese Patent Laid-Open Publication No. SHO-60-107079 shows a technique which prestores many kinds of note patterns (patterns of pitch variation tendency and note combination) for a single measure and selects a desired one of the prestored note patterns so as to automatically compose a music piece comprised of a plurality of measures. This technique, however, can only compose a music piece with a limited note combination (positions of individual positions within a measure) because the note combination is fixedly contained in the pattern.
Moreover, Japanese Patent Laid-open Publication No. HEI-6-75576 discloses a technique which prestores many pieces of correlative melody information, selects a desired piece of the correlative melody information for convolutional integral operations thereon so as to form melody outline information (information indicative of a time-varying pitch tendency), and automatically composes a music piece on the basis of the melody outline information. However, this publication fails to describe in detail a manner in which notes are allocated to the formed melody outline and only discloses that a music piece is created by entering musical rules.
Because the known automatic composing techniques in the filed of computer music as discussed above are merely based on such processing as to satisfy a variety of preset musical conditions (such as a chord progression, musical genre and rhythm (type), they can not perform normal composing operations hitherto done by a human being, such as first creating words and then creating music suitable for the words.
Further, in the prior art automatic music composing devices which analyze melodic characteristics of an original music piece and compose a new music piece on the basis of results of the analysis, the analysis results were used directly without being substantially modified. Even where the analysis results were modified partly, the partial modification did not mean anything more than mere random rewriting of the analysis results, due to the fact that it could not be clearly recognized how the modification acts in the course of the automatic composition. Therefore, these automatic music composing devices could not achieve automatic composition of a music piece as contemplated by an operator or user.